While I hope the new plan to reduce the late night fighting in the Old Port helps, I think allowing some bars to stay open later would be more effective. The reason there are huge crowds in the old port is because everyone is getting pushed out of the bars at 1:00 a.m. If you let bars stay open later, people would gradually head out and there would not be the big rush all at once. The bars that close later can stop letting customers in after a certain point so people can't go out to see if there is crowd, then go back in to keep drinking and wait for a crowd.
Besides, there are a lot of people (including those tourist who are looking to have fun) who will gladly spend money well past 1:00 a.m. I realize allowing some people to keep drinking past 1:00 can cause problems, but I think most places in the country allow bars to open much later, and they don't seem to have the same problems.